Suspension for a reciprocable blade of a shaver head



April 7, 1970 B F TER R 3,504,433

SUSPENSION FOR A RECIPROCABLE BLADE OF A SHAVER HEAD Filed June 6, 19672 Sheets-Sheet 1 9 I Fig. 2

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SUSPENSION FOR A RECIPROCABLE BLADE OF A SHAVER HEAD Filed June 6, 19672 Sheets-Sheet 2 FIG. 7 FIG. 8

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" United States Patent 3,504,433 SUSPENSION FOR A RECIPROCABLE BLAD OF ASHAVER HEAD Bodo Fiitterer, Sarnen, Obwalden, Switzerland, assignor,

by mesne assignments, to The Gillette Company, Boston, Mass., acorporation of Delaware Continuation-impart of application Ser. No.514,541, Dec. 17, 1965. This application June 6, 1967, Ser. No. 643,991

Int. Cl. B2611 19/02 US. Cl. 3043.92 12 Claims ABSTRACT OF THEDISCLOSURE A shaver head having a reciprocating cutter blade cooperatingwith a shear comb and resilient suspension means maintaining said cutterblade relative to said shear com-b. The resilient suspension means isconnected to a support to which a shear comb is rigidly mounted, and,also, is connected to the reciprocable cutter blade so as to resilientlyurge the cutter blade into intimate contact with the shear comb andinsure rectilinear longitudinal movement of the cutter blade.

This application is a continuation-in-part of my copending applicationSer. No. 514,541, filed Dec. 17, 1965, now abandoned.

My present invention relates to a suspension for a reciprocable blade ofa shaver head cooperating, in the usual manner, with an adjoiningstationary shear comb which is rigid with a fixed support and which maytake the form of a perforated foil, e.g., as described in my saidcopending application.

As the reciprocating blade must remain in intimate contact with thefixed shear comb at all points in order to afford a close shave, it isnecessary in the case of flat Shavers to provide this blade withsuspension means ensuring it rectilinear longitudinal movement. The useof straight guide rails for this purpose has proved to be unsatisfactorysince it generates a considerable amount of friction; where thisfriction is reduced by the interposition of ball or roller bearings,objectionable chattering or noise of the shaver may ensue.

It is, therefore, a main object of my present invention to provide animproved blade suspension for such shaver heads which ensures arectilinear reciprocating motion of the blade or cutter with a minimalof frictional resistance and without objectionable noise.

A further object is to provide means in such shaver head for exertingupon an elongated holder, designed to carry the reciprocable blade, apositive force resiliently urging the blade in intimate contact with thestationary shear comb without generation of excessive friction betweenthe cooperating cutting elements.

A still further object is to provide an improved blade suspension forsuch shaver heads which is of simple construction and does not affordany maintenance.

The invention provides an improved blade suspension of compact designwhich enables the construction of electric safety razors of minimizedvolume.

Still another object resides in providing an improved blade suspensionof easy construction, which resiliently urges the cutter blade against astationary shear comb.

The main object is realized, in conformity with my present invention, bythe provision of a pair of elongated spring means, each being connectedto opposite ends of a cutter blade holder. Another pair of elongatedspring means, which are rigidly connected with one of their end to afixed support for said shear comb or to the casing of the shaver, arebeing arranged in adjacent and approximately parallel relationship or inan acute angle to said first pair of elongated spring means, and beingarranged such that the free ends of adjacent spring means, e.g., thoseends, which are not fastened at the cutter blade holder and at the fixedsupport, aredisposed adjacent each other and are being rigidlyconnected. The stiffness and the lengths of said spring means are chosenin such a manner that upon deflection of the cutter blade holder thecomponents of the lengths of all spring means perpendicular to thedirection of movement of the cutter blade holder decrease about equalamounts.

The above mentioned and other objects and novel features of my presentinvention will appear more fully hereinafter from the following detaileddescription of the invention when taken in connection with accompanyingdrawings wherein several embodiments of my invention are illustrated. Itis to be expressly understood, however, that the drawings are utilizedfor purposes of illustration only and are not designed as a definitionof the limits of the invention, reference being had for this purpose tothe appended claims.

In the drawings:

FIG. 1 is a front elevation view of a suspension means according to myinvention;

FIG. 2 is a side elevation view of a cutter blade holder together with amounting therefor in cooperation with a pair of suspension means asshown in FIG. 1;

FIG. 3 is a top plan view (parts broken away) of the assembly of FIG. 2;

FIG. 4 is a view similar to FIG. 1 showing a modified suspension meansadapted for the use in the assembly of FIGS. 2 and 3;

FIG. 5 is a perspective view of an assembly similar to that of FIGS. 2and 3 but with a further modification of its suspension means;

FIG. 6 is a view similar to FIGS. 1 and 4, illustrating still anothermodification;

FIG. 7 is a view similar to FIG. 1 showing a suspension means whereinthe elongated spring means are of unequal length;

FIG. 8 is a view similar to FIG. 1 showing another suspension means withelongated spring means of unequal length;

-FIG. 9 is a side view of a modification of the suspension means shownin FIG. 8;

FIG. 10 is a view similar to FIG. 1 showing a suspension means made ofspring wire.

In FIG. 1 I have shown a resilient suspension leaf 11 comprising threeupstanding legs 11a, 11b, the central leg 11b being flanked by the outerlegs 11a and having a width equal to the sum of the widths of theseouter legs. Mounting holes 12 in legs 11a and 13 in leg 11b serve forthe passage of screws or other fastening means for securing thesuspension leaf 11 to a fixed support 14 and to a cutter blade holder 15as illustrated in FIGS. 2 and 3.

The cutter blade holder 15 is an elongated bar attached at opposite endsto the center legs 11b of two resilient suspension leaves 11 whose outerlegs 11a are fastened to the support 14 forming part of a shaver head.This support is rigid with a shear comb 18 overlying a movable blade 19which is detachably mounted on the bar 15 through the intermediary of aboss 16. Support 14 is shown recessed at 14a to accommodate the centerleg 11b of either suspension leaf 11 when the holder 15 is reciprocatedby conventional drive means not shown, in the direction of arrow A ofFIG. 2. This holder has a neutral position in which the legs 11b of thetwo suspension leaves just clear the recesses 14a and are coplanar withthe respective legs 11a. As the holder 15 moves out of this neutralposition, the legs 11a and 11b of each suspension leaf form oppositearms of an upstanding V whose vertex rises with increasing spread of thelegs; the upper ends of the legs, however, remain on the same level,i.e., the level of attachment of legs 11a to support 14, so that theblade 19 on its holder 15 stays in the same horizontal plane as itreciprocates next to the counterblade 18. This is true because the legs11a, 11b deflect symmetrically from their coplanar position by virtue ofthe fact that in confronting cross-sections, i.e., at the same distancefrom their integral junction 11c, they have equal moduli of fiexuralresistance.

FIG. 4 shows an alternate suspension leaf 21 whose legs 21a, 21b,respectively provided with mounting'holes 22 and 23, differ from thoseof suspension leaf 11 by progressively diminishing in cross-sectiontoward the midpoint of their length so as to exhibit a substantiallyconstant specific bending stress. This stress distribution enables thesuspension leaves to be made thinner than in the preceding embodimentfor a given amplitude of reciprocating movement. Naturally, the taperingof the cross-section of each leg could also occur in the thicknessdimension thereof. Again, as before, the sum of the widths of the outerlegs 21a equals that of the inner leg 21b at any given distance from thejunction 210.

In FIG. I have shown a pair of suspension members 31 whose legs 31a, 31bare bent at the top into the plane of the cutter blade holder 35. Theholder 35 in this case forms an integral extension of the central legs31b of both suspension members, the assembly here being advantageouslymolded from a resilient plastic material. Mounting holes 32 set at thefree ends of legs 31a serve again to attach the assembly to the wall ofthe shaver head. The reciprocable cutter blade 39 is mounted on a holder35 via a boss 36.

In this embodiment the integral junction between the legs 31a, 31b .ofeach suspension member 31 is formed As shown in FIG. 6, it is possibleto complement the i disclosed suspension members by a second junction41d of their legs 41a, 41b located, substantially mirror-symmetricallywith reference to the first junction 410, on the opposite side of theirpoints of connection as represented by mounting holes 42, 43. Thissymmetrical suspension 41 could, of course, be modified in the mannerillustrated in FIG. 4 so as to have a substantially constant bendingstress throughout the length of each leg.

FIG. 7 shows a further modification of the suspension member shown inFIG. 1, wherein the central leg 51b is longer than each of the outerlegs 51a, so that the cutter blade holder when fastened (not shown) atmounting holes 53 of the inner leg, may overtop the free ends of outerlegs 51a provided with mounting holes 52 for attaching the suspensionmember at the support of the shear comb (not shown) or at the casing ofthe shaver. This Embodiment is particularly useful for shavers ofcompact esign.

FIG. 8 shows an alternate suspension leaf 61 whose legs I 61a, 61b,respectively provided with mounting holes 62 and 63, are of unequallength. This embodiment is similar to that of FIG. 7, except that theouter legs 61a are longer than the central leg 61b. Advantageously thecutter blade holder (not shown) should be fastened at mounting holes 62of the outer legs 61a, whereas the central leg 61b is secured withmounting holes 63 at a fixed support or casing.

Generally, the elongated spring means of each suspension means may liein a common plane. However, as is shown in the cross-sectional or sideview of FIG. 9, the inner leg 71b may form an acute angle 'with each ofthe outer legs 71a, thus providing asuspension that is not onlyresilient in the direction of the reciprocating movement, but also in aperpendicular direction thereto.

FIG- 10 ill s ra es a s p nsion means made of p ng- J; 4 wire. The inneror central leg 81b has an elongated loop portion 83 which serves asmounting means of the central leg. The open end of said loop portion iscontinued by a pair of spring-wire portions 84 being arranged inparallel and adjoining relationship about part of their length, thusforming the central leg, and being bent back at 85 to form a pair ofouter legs 86. Loops 82 are formed at the ends of the outer legs toserve as mounting means. The suspension means according to FIG. 10 isself-centering since it is resilient in three orthogonal directions.Resiliency in a direction perpendicular to'the direction of movement ofthe cutter blade holder may be increased by forming an acute anglebetween the central leg 81b and the outer legs 81:: in the plane ofmovement of the suspension member in the neutral position of the same.

It is within the scope of my invention to rigidly secure either thecentral leg or the outer leg or legs whereas the other legs may bearticulated at parts of the razor. Further, it should be recognized thatthe benefits of my invention will be present if the central leg as wellas the outer legs were articulated at the respective parts of the razor.In this case, of course, one must take care of avoiding unstable staticconditions, and to this end all legs of each suspension member shouldlie within a common plane. However, it is more advantageous to rigidlysecure at least one resilient means or leg of each suspension means atcoordinated parts of the razor.

It will be well aware to those skilled in the art that my inventionprovides a rectilinear reciprocating movement of the movable end of mysuspension means by combining the oscillatory movements of two resilientmeans, both being arranged in approximately anti-parallel relationshipand the suspension end of one of said resilient means being stationary,whereas the suspension end of the other resilient means is coupled tothe oscillating end of the aforementioned resilient means. Thus, a sortof double-pendulum is formed whereby one pendulum is hinged at the otherone and is turned about degrees in its neutral position. It is withinthe knowledge of those skilled in the art to find the length of each ofthe resilient means of my suspension means for given values offlexibility of the same, vice versa.

What I claim is:' y

1. In a shaver head comprising a reciprocable cutter blade disposed inintimate contact with a stationary shear comb, the combination therewithof suspension means for movably securing said cutter blade to a fixedsupport of said shear comb, said suspension means comprising anelongated cutter blade holder, first resilient means con-' nected withone of its ends to one end of said cutter blade holder, second resilientmeans connected with one of its ends to the other end of said cutterblade holder, third resilient means connected with one of its ends tosaid fixed support, fourth resilient means connected with one of itsends to said fixed support, said third and fourth resilient means beingarranged in adjacent and parallel relationship to said first and secondresilient means, respectively, and being arranged thus that the freeends of adjacent resilient mean are disposed adjacent each other, firstconnecting means fixedly connecting the'free ends of said first andthird resilient means with one another, second connecting means fixedlyconnecting the free ends of said second and fourth resilient mean withone another, and the dimensioning of said resilient means such that atat least one definite deflection of the cutter blade holder thecomponents of the length of said first, second, third and fourthresilient means normal to the direction of movement of said cutter bladeholder have decreased about equal amounts.

2. The combination and dimensioningdefined in claim 1 wherein saidresilient means consist of leaf springs.

3. The combination and dimensioning defined in claim 1, wherein saidresilient means are of equal length.

4. The combination and dimensioning defined in claim 1. Whcrcin. saidfirst and second resilient means form integral parts with said third andfourth resilient means, respectively.

5. The combination and dimensioning defined in claim 1 wherein at leastone of said resilient means at each side of the cutter blade holderconsists of a pair of elongated springs flanking the other one of saidresilient means at the respective side of the cutter blade holder.

6. The combination and dimensioning defined in claim 1 wherein saidresilient means form elongated springs the cross-sectional area of whichprogressively decrease toward a mid-point of their length.

7. The combination and dimensioning defined in claim 1 wherein saidfirst and second connecting means form rod-shaped portions integral withsaid free ends of said resilient means at each side of the cutter bladeholder.

8. The combination and dimensioning defined in claim 1 wherein a secondset of resilient means and of connecting means is provided and arrangedmirror-picture like relative to the first set of resilient means and ofconnecting means.

9. In a shaver head comprising a reciprocable cutter blade disposed inintimate contact with a stationary shear comb, the combination therewithof suspension means for movably securing said cutter blade to a fixedsupport of said shear comb, said suspension means comprising anelongated cutter blade holder, first elongated spring means connectedwith one of its ends to one end of said cutter blade holder, secondelongated spring means connected with one of its ends to the other endof the cutter blade holder, third elongated spring means connected withone of its ends to said fixed support, fourth elongated spring meansconnected with one of its ends to said fixed support, said third andfourth elongated spring means being arranged in adjacent and parallelrelationship to said first and second elongated spring means,respectively, and being arranged such that the free ends of adjacentspring means are disposed adjacent each other, said free ends ofadjacent spring means being integrally connected with one another, andthe dimensioning of said spring means such that at any deflection of thecutter blade holder the components of the lengths of said first, second,third, and fourth spring means normal to the direction of movement ofsaid cutter blade holder have decreased about equal amounts relative totheir neutral positions.

10. The combination and dimensioning defined in claim 9 wherein saidfirst and second elongated spring means are unequal in length to saidthird and fourth elongated spring means.

' 11. In a shaver head comprising a reciprocable cutter blade disposedin intimate contact with a stationary shear comb, the combinationtherewith of suspension means for movably securing said cutter blade toa fixed support of said shear comb, said suspension means comprising anelongated cutter blade holder, first elongated spring means connectedwith one of its ends to one end of said cutter blade holder, secondelongated spring means connected with one of its ends to the other endof said cutter blade holder, third elongated spring means rigidlyconnected with one of its ends to said fixed support, fourth elongatedspring means rigidly connected with one of its ends to said fixedsupport, said third and fourth elongated spring means being arrangedadjacent to and forming an acute angle with said first and second springmeans, respectively, and being arranged such that the free ends ofadjacent spring means are disposed adjacent each other, said free endsof adjacent spring means being integrally connected with one another,and the dimensioning of said spring means such that at least onedefinite deflection of the cutter blade holder the components of thelengths of said first, second, third and fourth spring means normal tothe direction of movement of said cutter blade holder have decreasedabout equal amounts relative to their neutral positions.

12. The combination and dimensioning defined vin claim 11 wherein saidfirst and second spring means are rigidly connected to said cutter bladeholder.

References Cited UNITED STATES PATENTS 2,530,759 11/1950 Collins et a1.3041.6 X 3,105,298 10/1963 Carissimi 3043.92 3,144,714 8/1964 Beisma30-4392 ROBERT C. RIOR'DON, Primary Examiner G. F. GRAFEL, AssistantExaminer

